works great for me. Depends on what you need / want it for. Mine was $200. They can have multiple programs if you get a flip switch so you can have a program w/ a 3K rev limiter if ya want for valet, or who ever may drive your car you don't trust, mechanic, looser friends

or whatever
w/it you can also -
lower fan turn on temp
tune a/f ratios
calibrate speedo for gears
turn off engine light for off road exhaust
set rev limiter higher / lower
other stuff I'm sure I forgot too.